In the dyeing of cellulosic textile materials and/or the printing thereof, it has been recognized that it is necessary to utilize various reactive compounds of an electropositive character to improve the fixing of the dyestuff on the fabric. Dyestuffs are employed of different characteristics for different textile material and, in general, some fabric are less susceptible to dyeing with certain dyestuffs. Consequently, it has been recognized that there are certain additives which can be used to treat the fabric beforehand and/or simultaneously with the dyestuff to improve dye takeup and the fixing of the dyestuff to the fabric.
It is known to use an epoxy ammonium compound having the following formula: ##STR2## wherein R, R', and R" are alkyl radicals having from 1 to 20 carbon atoms R"' is an alkylene radical having from 1 to 20 carbon atoms, while X-- is an anionic group such as the sulfate group, the sulfonate group or a halide group. The halides which may be used are fluoride, chloride, bromide or iodide.
The additive may be utilized in two distinct processes. The epoxy compound may be applied to the textile material within the dyeing bath or the printing pastes, i.e. in the presence of the dyestuff which is to be taken up by the textile material. Also, the fabric prior to carrying out the dyeing process can be treated with the epoxy compound.
It is known to fix the additive to cellulosic materials in the presence of an alkaline substance whose concentration increases inversely with the treatment temperature. In other words, higher concentrations of the alkaline substance are necessary with lower temperatures, and higher temperatures are required when lower concentrations of the alkaline substance are used. Generally, the alkaline substance is a strong base, preferably caustic soda, and extremely high concentrations are applied by the prior art to ensure fixation at low temperatures.
However, treatments at elevated temperatures have become preferable to lowertemperature treatments utilized in the prior art because of faster processing and higher yields obtainable in industrial equipment.
It is known that treatment of the textile material at high temperature, after it has been impregnated with the epoxypropylammonium salt, gives rise invariably to a strong yellowing thereof. The yellowing may not be removed in the course of the usual subsequent treatments.
Such yellowing constitutes a considerable handicap to the use of the epoxypropylammonium salts at high temperatures.
The yellowing modifies or dulls the desired color and makes it impossible to obtain a white background in the printing of fabrics.
U.S. Pat. No. 3,685,953 to Cuvelier et al discloses a process of treating a hydrolyzed polymer such as cellulose with an epoxypropylammonium salt of the invention or the corresponding chlorohydrin and then drying at a high temperature. However, the process results in low yields.
U.S. Pat. No. 3,853,460 to Balland relates to the use of alkylsulfosuccinates and alkylsulfosuccinamates with epoxypropylammonium salts to prevent hydrolysis of the compound to the dihydroxy compound.
U.S. Pat. No. 4,072,464 to Balland relates to the use of boric acid with an epoxypropylammonium salt to improve dye penetration of a cellulosic fabric and to decrease yellowing. The fabric is then heat treated at an elevated temperature.
U.S. Pat. No. 4,035,145 relates to the use of N-(2,3-epoxyalkyl) ammonium salts such as N-methyl-N-(2,3-epoxypropyl)-morpholinium chloride in the presence of alkaline compounds to improve the dyeability of cellulosic textiles.
U.S. Pat. No. 5,006,125 to Patton et al discloses the use of an epoxypropyl ammonium salt or the corresponding chlorohydrin to improve the bleaching process of cellulosic fabrics.
It is understood that the term "polyhydroxylized polymer" as used herein relates to natural and synthetic polymers containing free hydroxyl groups which include cotton, flax, linen, rayon, polyvinyl alcohol, and the like.
The term "fabric" as used herein refers to fibers, yarns, tows, mats, battings, cloth, and the like which comprise the polyhydroxylized polymer alone or in blends with other natural or synthetic fibers such as wool, polyester, nylon, etc.